U.S. patent number 9,441,732 [Application Number 14/659,703] was granted by the patent office on 2016-09-13 for regulator valve with integrated direct acting solenoid.
This patent grant is currently assigned to FORD GLOBAL TECHNOLOGIES, LLC. The grantee listed for this patent is FORD GLOBAL TECHNOLOGIES, LLC. Invention is credited to Robert O. Burkhart, John Butwin, Derek Kinch, Anthony G. Koenings, Hrudaya Mahapatro, Wei Zhuang.
United States Patent |
9,441,732 |
Burkhart , et al. |
September 13, 2016 |
Regulator valve with integrated direct acting solenoid
Abstract
A control valve for an automatic transmission includes a valve
body including a chamber and a control pressure port, metering
edges formed in the valve body at the control pressure port, a
reference surface formed in the valve body, a spool displaceable
along the chamber, and a solenoid module including a pin for
displacing the spool, and located in the chamber by contact with
the reference surface.
Inventors: |
Burkhart; Robert O. (Novi,
MI), Kinch; Derek (Ypsilanti, MI), Butwin; John (An
Arbor, MI), Koenings; Anthony G. (Oakland, MI),
Mahapatro; Hrudaya (Canton, MI), Zhuang; Wei (Canton,
MI) |
Applicant: |
Name |
City |
State |
Country |
Type |
FORD GLOBAL TECHNOLOGIES, LLC |
Dearborn |
MI |
US |
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Assignee: |
FORD GLOBAL TECHNOLOGIES, LLC
(Dearborn, MI)
|
Family
ID: |
47596467 |
Appl.
No.: |
14/659,703 |
Filed: |
March 17, 2015 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20150184741 A1 |
Jul 2, 2015 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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13192807 |
Jul 28, 2011 |
9010374 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16K
31/0613 (20130101); F16H 61/0251 (20130101); Y10T
137/86614 (20150401); Y10T 137/8671 (20150401); Y10T
137/86622 (20150401); F16H 2061/0253 (20130101) |
Current International
Class: |
F16K
31/06 (20060101); F16H 61/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Murphy; Kevin
Attorney, Agent or Firm: Dottavio; James MacMillan, Sobanski
& Todd, LLC
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
The present patent application claims the benefit of and is a
divisional of U.S. patent application Ser. No. 13/192,807, filed
Jul. 28, 2011, which is incorporated herein by reference.
Claims
What is claimed is:
1. A valve, comprising: a single monolithic body including an
integral chamber, exhaust port and an integral control pressure
port; first and second edges integral with the body at the control
port and exhaust port, respectively; a reference surface integral
with the body; a spool displaceable along the chamber; a solenoid
module, including a pin for displacing the spool, located in the
chamber by contact with the reference surface; and wherein the
solenoid module includes a first stop surface for limiting movement
of the pin in the chamber, and a second stop surface able to
contact the reference surface; and the spool includes a second land
that contacts the second stop surface when the spool moves in the
chamber before the pin contacts the first stop surface.
2. The valve of claim 1, wherein the spool is formed with a land
that opens and closes communication between the chamber and the
control pressure port across the first edges and between the
chamber and the exhaust port across the second edges.
3. The valve of claim 2, wherein: the spool includes consecutive,
axially-spaced third and fourth lands, the third land having a
cross sectional area less than a cross sectional area of the fourth
land, the third land defining a damping chamber in the chamber, a
cross sectional area of the damping chamber being greater than a
difference between said areas of the third and fourth lands.
4. The valve of claim 3, wherein the damping chamber is in
hydraulic communication with the control pressure port.
5. The valve of claim 1, further comprising: a spring urging the
spool against the pin; a second spring urging the pin toward the
spool; and a solenoid for producing a magnetic force that opposes a
force of the spring and displacing the spool and pin when the
solenoid is energized, and allowing the force of the spring to
displace the spool and pin when the solenoid is deenergized.
6. The valve of claim 1, wherein the first edge is located on a
first axial side of the control pressure port, and the second edge
is located on a second axial side of the exhaust port opposite the
first axial side; further comprising a line pressure port
communicating a source of line pressure to the chamber, a land
opening a connection between the control pressure port and the line
pressure port across the first edge.
7. The valve of claim 1, wherein the first edge is located on a
first axial side of the control pressure port, and the second edge
is located on a second axial side of the pressure port opposite the
first axial side, a land opening a connection between the chamber
and the control pressure port across the second edge.
8. The valve of claim 1, wherein: the solenoid module includes an
adapter that forms the second stop surface.
9. The valve of claim 8, wherein: the second stop surface is urged
into contact with the reference surface by an elastic force
produced by a resilient retainer secured to the solenoid
module.
10. A valve, comprising: a single monolithic body including a
chamber, exhaust port, control pressure port and reference surface;
first and second edges integral with the body at the control port
and exhaust port, respectively; a spool displaceable along the
chamber; a solenoid module, including a pin for displacing the
spool, located by contact with the reference surface, and a first
stop surface limiting pin movement, and a second stop surface
contacting the reference surface; and wherein the spool includes
consecutive, axially-spaced third and fourth lands, the third land
having a cross sectional area less than a cross sectional area of
the fourth land, the third land defining a damping chamber in the
chamber, a cross sectional area of the damping chamber being
greater than a difference between said areas of the third and
fourth lands, and wherein the damping chamber is in hydraulic
communication with the control pressure port.
11. The valve of claim 10, wherein the spool includes a second land
that contacts the second stop surface when the spool moves in the
chamber before the pin contacts the first stop surface.
12. The valve of claim 10, wherein: the second stop surface is
formed on an adapter contacting the reference surface; and the
spool includes a second land that contacts the second stop surface
when the spool moves in the chamber before the pin contacts the
first stop surface.
13. The valve of claim 12, wherein: the second stop surface is
urged into contact with the reference surface by an elastic force
produced by a resilient retainer secured to the solenoid
module.
14. A valve, comprising: a body including a chamber, exhaust port
and control pressure port; first and second edges formed in the
body at the control port and exhaust port, respectively; a
reference surface formed in the body; a spool displaceable along
the chamber; a solenoid module, including a pin for displacing the
spool, located in the chamber by contact with the reference
surface, and a first stop surface for limiting movement of the pin
in the chamber, and an adapter formed with a second stop surface
contacting the reference surface; and wherein the spool includes a
second land that contacts the second stop surface when the spool
moves in the chamber before the pin contacts the first stop
surface.
15. The valve of claim 14 wherein, the second stop surface is urged
into contact with the reference surface by an elastic force
produced by a resilient retainer secured to the solenoid module.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a regulator spool valve
controlled by a direct acting solenoid located in a machined main
control casting of an automatic transmission.
2. Description of the Prior Art
An automatic transmission includes a hydraulic system for
regulating fluid pressure and hydraulic fluid flow in various lines
connected to components of the transmission. The system includes a
regulator spool valve packaged in a main control casting, which is
machined at a transmission production plant. The casting,
preferably of an aluminum alloy, is usually referred to as a valve
body. The components of the system are assembled in the valve body
and have transfer functions characterized at the plant.
A solenoid-actuated shift valve controls pressure communicated from
the valve to a clutch or brake whose state of engagement and
disengagement determines the gear in which the transmission
operates. But the dimensional tolerance stack-up in most valve body
castings is too large to permit use of a practical integrated
electromagnet and achieve required flow and pressure regulation
accuracy.
A need exists in the industry for a regulator spool valve formed in
a valve body and having an electric solenoid directly integrated
into the valve such that the dimensional tolerances are not an
obstacle to accuracy of pressure regulation and fluid flow.
SUMMARY OF THE INVENTION
A control valve for an automatic transmission includes a valve body
including a chamber and a control pressure port, metering edges in
the valve body at the control pressure port, a reference surface in
the valve body, a spool displaceable along the chamber, and a
solenoid module including a pin for displacing the spool, and
located in the chamber by contact with the reference surface.
The control valve allows elimination of the conventional solenoid
valve body, while maintaining regulator valve custom tuning at each
friction control element without adding solenoid complexity. A
hydraulic system that includes the control valve contains fewer
components, thereby lowering production and assembly costs. The
casting integration provides ability to include a latch function or
multiple latch functions to the regulator valve.
The reference structure and machining allows for significantly
reduced displacement or travel of the spool, thereby enabling use
of a direct acting solenoid to control location of the spool in the
valve chamber within cast body.
The integrated hydraulic control portion of the solenoid allows for
reduction of space required for solenoid and flow passages, as no
additional sleeve, manifold or porting is required.
The same magnetic motor can be used to drive different spool valve
configurations within the same valve body casting adapted to
differences in the hydraulic circuit. The embodiment shown produces
higher pressure as current increases, the direction of application
of the electromagnetic force may be reversed to provide high
pressure at low current. Reduced leakage results due to elimination
of interface between an electro-hydraulic solenoid sleeve\flange
and rest of the control body.
The scope of applicability of the preferred embodiment will become
apparent from the following detailed description, claims and
drawings. It should be understood, that the description and
specific examples, although indicating preferred embodiments of the
invention, are given by way of illustration only. Various changes
and modifications to the described embodiments and examples will
become apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood by reference to the
following description, taken with the accompanying drawings, in
which:
FIG. 1 is a schematic showing a cross section of a Meter Out--Meter
In (MOMI) casting-integrated direct acting solenoid valve with
latch valve;
FIG. 2 is a cross section of the casting-integrated direct acting
solenoid of FIG. 1;
FIG. 3 is a schematic showing a casting-integrated direct acting
solenoid valve showing a Meter Out--Meter Out (MOMO)
configuration;
FIG. 4 is a graph showing the variation of outlet pressure in
response to current; and
FIG. 5 includes graphs of delatch pressure and regulating spool
position while the latch valve is delatched.
DETAILED DESCRIPTION
The casting-integrated, direct acting solenoid hydraulic valve 10
shown in FIGS. 1 and 2 includes a valve body 12 formed of cast
metal, preferably an aluminum alloy. The valve body 12 contains a
valve spool 14, formed with lands 16-19; an optional compression
spring 20 urging the spool rightward; an armature pin 24 contacting
the spool; an electromagnetic solenoid 26, which actuates the pin
to move leftward when the solenoid is energized and allows the
spool to move rightward when the solenoid is deenergized; and a
second optional compression spring 28 biasing the pin leftward.
Preferably spring 20 has a relatively low spring constant to make
most use of available force from electromagnetic solenoid 26.
The valve body 12 is formed with control ports 30, 42 through which
control pressure communicates with the chamber 32 containing the
spool 14; a line pressure port 34, through which line pressure
communicates with the chamber; sump port 36, through which
hydraulic fluid flows from the chamber to a low pressure sump; and
an exhaust ports 38, 40, through which the chamber communicates
with a low pressure source.
Adapter 22 or snout is continually held in contact with an
installation datum or reference surface 46 formed in sump port 36
by the elastic force produced by a resilient clip 44, which is
secured to the outer surface of a housing 45 that encloses the
solenoid 26.
A single tool concurrently machines both of the metering edges 48,
49 and the installation datum or reference surface 46 in the valve
body. The solenoid module 50 includes adapter 22 or snout, solenoid
26, housing 45 and spring 28.
All edges that requiring precise relative positions are cut in a
single operation for improved tolerances and manufacturing
efficiency. Metering edges are precision machined rather than cast
for improved edge quality, location accuracy, and zero draft. High
precision tolerances enable close control of leakage and pressure
regulation accuracy. Close tolerances enable flow control with a
short stroke solenoid module 50.
In operation, valve 10 regulates control pressure in port 30 and
feedback pressure in port 42 by producing a first sum of the force
of optional spring 20 and the rightward net force due to control
pressure in port 42 acting on the differential areas of lands 16
and 17. Balancing the first sum of forces is a second sum of
leftward forces comprising the force of the solenoid-actuated pin
24 and the force of spring 28. As the force of pin 24 increases,
valve 10 opens a connection through metering edge 49 between line
pressure in port 34 and control pressure in ports 30, 42. As
metering edge 49 open, control pressure increases. When control
pressure increases sufficiently for the current position of pin 24,
the differential feedback control pressure on lands 16, 17 causes
the metering edge 49 to close and metering edge 48 to open a
connection between control pressure port 30 and to the low pressure
exhaust through chamber 32, exhaust port 38 and passage 72.
A single metering control pressure port 30 at spool land 18 (Meter
Out--Meter In, as shown in FIG. 1) or a dual metering control
pressure ports 30, 38 at spool land 52 (Meter Out--Meter Out, as
shown FIG. 3) can be accommodated with no change in tolerances. A
clear division of tolerance responsibility is established for the
electromagnet and hydraulic manufacturing groups.
In FIG. 2 the diameter of control land 17 is larger than the
diameter of land 16 of valve 10. The diameter of land 16 of valve
10 defines a large diameter spool end damper 60 for enhancing
stability, permitting use of a relatively large diameter,
contamination resistant damper orifice 62. Damper 60 is formed
outside of the feedback path 64 for minimum feedback lag and
improved stability. The diameter of damper 60 is large relative to
the difference in diameter of the lands 16 and 17.
The large diameter of spool land 18 combined with flow notches
enables high flow with a short stroke magnet as well as the
preferred manufacturing technique.
The valves shown in FIGS. 1-3 enable standard main control
(multi-bore including worm trail) configurations while providing
magnet interface tolerances.
A control pressure bleed orifice 66 provides for spool position
control and stability. Tracking response is improved with no
dead-zone to cross. Low frequency hunting across the dead-zone is
also prevented.
Tight machining tolerances allow for minimized overlap reducing
dead band.
The axial surface 68 of adapter 22 or snout is located in chamber
32 due to contact with reference surface 46 such that, when
solenoid 26 is deenergized and spool 14 moves rightward in the
chamber, land 19 contacts surface 68 before the armature pin 24
contacts a stop surface 70 in the solenoid module, thereby
preventing spring 28 from becoming fully compressed due to contacts
among its coils. In this way, the spool end feature provides
positive stop for forced over travel protection of the solenoid
module 50.
Damping chamber 60 is provided with an oil reservoir using an
elevated vent 66 and fed from the control pressure bleed orifice
66.
The casting-integrated, direct acting solenoid configuration 10
(10'' in FIG. 3), includes a latch valve 80 formed in the valve
body 12 of cast metal. Valve 80 includes a spool 82, formed with
lands 84, 86; a compression spring 87 urging spool 82 rightward;
exhaust port 88; line port 90, connected to a source of line
pressure whose magnitude is substantially constant; an outlet port
92, through which a clutch or brake 94 of the transmission is
actuated; a control port 96 communicating through passage 64 with
control pressure ports 30, 42 of valve 10 (10'' in FIG. 3); and a
control pressure feedback port 98 also communicating through
passage 64 with control pressure ports 30, 42 of valve 10 (10'' in
FIG. 3).
In operation, valve 80 supplies actuating pressure through line 100
to the cylinder 102 of a hydraulic servo that actuate the
transmission control element 94. When control pressure is
relatively low, spring 87 forces spool 82 to the right-hand end of
the chamber, thereby closing line port 90, opening control port 96
and communicating fluid at control pressure to the control element
94 through outlet port 92 and line 100. As control pressure
increases, spool 82 moves axially leftward along the valve chamber
due to a force produced by control pressure in feedback port 98
acting in opposition to the force of spring 87. Land 86 gradually
closes port 96, and land 84 maintains line port 90 closed. As
control pressure increases further, land 86 closes control port 96,
and land 84 opens a connection between line port 90 and the control
element 94, thereby latching valve 80 and engaging control element
94 using line pressure, which is typically significantly higher
than the maximum regulated pressure of the valve 10 (10'' in FIG.
3). If control pressure increases further after valve 80 is
latched, line pressure alone is applied to fully engage the control
element 94. After the control element 94 becomes fully engaged,
line pressure can be reduced to improve efficiency. The spool 14 of
regulating valve 10 is maintained in its regulating position while
valve 80 is latched.
Valve 80 is delatched by reducing control pressure, which causes
land 84 to close line port 90, and land 86 to reopen a connection
between control port 96 and the transmission control element 94
through outlet port 92 and line 100.
FIG. 4 shows the variation of outlet pressure in port 92 in
response to current in solenoid 26. The first portion of the
relation occurs as control pressure is increased while control port
96 is connected to outlet port 92 and line port is closed. The
second portion 106 occurs after point 108 where control port 96
closes and constant line pressure through port 90 opens to outlet
port 92 fully engaging the control element at 110.
The feedback chamber 102 of valve 80 is not exhausted when valve 80
is latched, thereby eliminating the possibility of entrapping air
in the lines feeding control element 94. Because the feedback
chamber 102 of valve 80 is not exhausted when valve 80 is latched,
those lines need not be refilled when valve 80 is delatched.
The regulator valve 10 and latch valve 80 in combination provide
functional advantages in transition states of clutch control by
performing the latch transition away from the regulation control.
As FIG. 5 shows, upon delatching valve 80, the position 112 of
spool 14 of the regulator valve 10 remains in a control metering
position because its output pressure controls the actuating event
and provides superior transition regulation compared to a
VBS-regulator-latch valve system 114.
A VBS-regulator-latch system commonly experiences pressure
undershoots 116 past the desired delatch pressure 118, whereas the
delatch pressure transient 120 produced by the combination of
valves 10, 80 closely tracks the desired delatch pressure 118 with
virtually no overshoot.
In accordance with the provisions of the patent statutes, the
preferred embodiment has been described. However, it should be
noted that the alternate embodiments can be practiced otherwise
than as specifically illustrated and described.
* * * * *